Five days, one T.V., 65 hours of courtroom drama, 150 cases. My afternoons have been spent in the company of jurists like Judge Sheindlin of "Judge Judy," Marilyn Milian of "The People's Court," and Judge Mablean Ephriam of "Divorce Court"modern-day Solomons who deliberate for an entire commercial break before extending the long arm of the law over the bench to slap the litigants silly. My nights have been spent at the feet of the giants of the T.V. benchnine once-a-week Supreme Court justices, a babe of a family-court judge, and a bunch of world-weary gavel-pounders who often sigh irritably before ruling.

I've learned a lot about judges in my hours on the couch. Thanks to reruns of "L.A. Law," I know that if a district attorney and a public defender are sniping at each other in court, the judge will ask them to approach the bench and inquire if they're hot for each other. From "Divorce Court," I've learned that when a scrapping couple goes to court, a helpful judge will advise them that if they were going to be so damn critical of each other, they should never have gotten married in the first place. And from "Law & Order," I've learned that when a judge hears a motion, he often gets up from the bench and takes a stroll around the courtroom in the company of the lawyers. It's more intimate that way, and if there's one thing a judge doesn't like, it's all that stuffy protocol.

There are two kinds of U.S. courts: daytime and prime-time. The difference is largely in the lighting. Daytime courts are brightly lit, whereas prime-time courts are dimmed by Venetian blinds that cast ominous, slanted shadows on the witnesses. Daytime judges are loud and tend to interrupt the litigants to make speeches, while prime-time judges speak in a dyspeptic murmur and wait until the last five minutes to speechify. In prime-time, no case goes to trial unless it involves a tricky ethical dilemma, an appalling murder, and an annoying defendantan arrogant network executive, say, or a pompous art dealer with trendy eyeglasses and a German accent. During the day, no dispute is too small or mundane of plot to merit its day in court, whether it's a feverish argument over the ownership of a rusty pizza oven or a teenage girl's accusation that her boyfriend's cousin got drunk and drove her car into a boulder. The judges in these courts seem to find trying cases on television to be a terrible imposition, but they do it anyway because somebody's got to tell these losers to get a life.

In daytime, the judge's main job is to figure out whether it's the plaintiff or the defendant who lies like a rug. Usually, the judge can tell by studying the litigants' faces. If you're appearing in this kind of case, it's a good idea to roll your eyes or assume an expression of open-mouthed disbelief while your adversary is making his pitch. Smirking, on the other hand, will get you into trouble. Judge Milian of "The People's Court" explained the art of lie detection to a defendant with a Latrell Sprewell hairdo and a Cheshire Cat smile who was accused of owing a former girlfriend $895.36 for his share of a joint gym membership. "I wouldn't believe you if your tongue was notarized," she said, "because of the grin that you can't seem to wipe off of your face."

On those troubling occasions when judges can't determine guilt at a glance, they ask probing questions about the relationship between the litigants like, "What were the rumors that she spread about you?" The litigants don't have to worry if their information comes third-hand. The only thing I ever saw ruled inadmissible was a witness in a strapless dress who was forbidden to enter the courtroom until she put on a sweater. Of course, a judge can also order a polygraph test, as Judge Larry Joe Doherty did on "Texas Justice." A woman named Julia Nelson was accusing her ex-roommate of owing her money for a phone bill. The roommate's defense was that she suspected Nelson of stealing money she'd left out on the dining room table, so why should she pay the bill? Judge Doherty was uncertain about the standard of proof in a criminal case, so in a time-honored tradition of judicial review, he consulted his bailiff. "What is it, William, in criminal courts . . . beyond a reasonable doubt?" It was, said William, and Doherty used a polygraph to remove all doubt that Nelson was a klepto whose pants were incontestably on fire.

The point is that doubt has no place in the well-run courtroom. I learned this from watching Court TV, which was offering gavel-to-gavel coverage of Michael J. Kantaras v. Linda Kantaras , a custody battle in Florida between a female-to-male transsexual and his ex-wife, who had produced a child with the help of sperm donated by Michael's brother. Soon after the first witness was sworn in, the network commentators attempted to reach their own verdict. "What's your call?" asked Nancy Grace, the wide-eyed Court TV anchor, addressing the assembled "family law experts." The experts thought Michael should prevail, either on the grounds that Linda knew her husband used to be a woman when she chose to have children with him, or on the grounds that everyone knows that transsexuals make the best parents. As one expert explained: "He's really a man that's in touch with his female side, which is the perfect custodial recipe."

With the verdict disposed of, the commentators were free to discuss other, more important issues. Did Michael Kantaras look like a man or a woman? ("He has quite a moustache there," observed Court TV's Fred Graham, the dean of T.V.'s legal journalists.) Was the judge, the Honorable Gerard O'Brien, uncomfortable with the issue of transsexuality? As one expert declared: "He's having therapy on the stand."

Well, why shouldn't he? Everyone else is. If you think legal rulings should be based on the law, you haven't watched enough television. Sure, every prime-time law drama has a scene of lawyers discussing a case in a room filled with law books. But no one ever actually takes a book down from the shelves. That's because legal decisions are based on how the judge feels . When Supreme Court Justices deliberate about a case they're going to rule on, as they do weekly on the show "First Monday," one of them might say she thinks that constitutional protections can be curbed in a time of war, and another one might say that that's what happened in Nazi Germany, and then they take a vote. And you know what? The Nazis lose.

Because judges have finely tuned moral compasses. They know that Nazis are bad, which is why anyone who can be associated with a Nazi has no chance in court. Take the case of the bullied teenager who came before Family Court Judge Amy Gray on "Judging Amy" because school officials were afraid he might pull a Columbine. Many in the courtroom thought the school was overreacting to an offhand remark the teenager had made, until Judge Amy asked him why he had written a school report on the Holocaust. The teenager replied that he thought the concentration camps were "interesting"and we all know what that means. Amy explained to the teenager that he made her "uneasy" and gaveled him off to criminal court, perhaps to be tried for felonious term-paper writing. That's the eerie thing about T.V. judges. They just know .

Dashka Slater is a journalist based in Oakland, Calif., and the author of a novel, The Wishing Box.